Rectifier



y 1945- G. H. SHOEMAKER 2,380,080

RECTIFIER Filed April '7, 1942 INVENTOR 6.1% J/memker A'ITORN EY Patented July 10, 1945 RECTIFIER George H. Shoemaker, Brookly N- Y., asslgnor to Federal Telephone and Radio Corporation, a corporation of Delaware Application April I, 1942, Serial No. 438,001

This invention relates to new and useful improvements in rectiflers and more particularly to selenium rectifiers.

He'retofore, selenium rectifiers were made by depositing a layer of selenium on a metal plate and then applying a continuous conducting coating to the exposed surface of the selenium with one or more metals or a suitable alloy.

In accordance with the present invention the conducting coating of the exposed siu'face of a selenium rectifier is divided into a plurality of distinct and electrically independent areas. A single rectifier disc so constructed may be connected into circuit as two rectifiers, e. g., in a center tapped rectifier connection or by connecting the separate areas in parallel. Each division of the rectifier may beused independently of the other,

The drawing illustrates in-Fig. 1 a top plan view and in Fig. 2 a vertical cross-section of an embodiment of the invention.

l is a selenium disc having a central perforation 2. The selenium is deposited on a metal plate 5. A suitable mask protecting the edge and a transverse stripe is applied to the exposed selenium surface and a metal alloy is sprayed r thereon. A metallic coating will form on the selenium in two mechanically and electrically distinct areas 3 and 4 laterally spaced from one another by a transverse stripe of selenium. The rectifier disc is then electrically formed, contact being made with both areas 3 and t.

After the customary testing and grading each half 3, 4 may be considered as an individual disc 0 in connecting the rectifier in circuit.

What is claimed is:

In a rectifier disc, a flat metal plate, a selenium layer thereon, and a conducting coating on the selenium layer, said disc having a central perforation extending through said plate, layer and coating, the coating being divided into a plurality of substantially equal areas covering the entire exposed selenium surface except a narrow stripe extending radially from the perforation between said areas and along the edge.

GEORGE H. SHOEMAKER. 

